Treatment of true superficial femoral artery aneurysms: the 15-year experience of a single centre (2024)

Abstract

Keywords: Femoral artery, Femoral aneurysm, Endovascular repair, Peripheral aneurysm

Introduction

True superficial femoral artery aneurysms (SFAAs) are rare because most cases are diagnosed late in life. Late diagnosis is usually related to the difficulty in recognising them earlier because they are located deep in the thigh and are not evident during physical examination unless they present as a painful pulsatile mass. Consequently, they continue to grow for many years until they reach considerable diameters and become symptomatic, mainly with symptoms related to mass compression of the adjacent vein and nerve structures. Moreover, non-mass-related symptoms include distal embolisation and rupture, which increase the risk of limb loss.¹ Open surgery has been the mainstay of treatment of SFAAs and involves mass decompression by opening the aneurysm sac followed by revascularisation with a prosthetic or vein graft.^2,3 The endovascular approach has recently gained popularity and is expected to become the preferred choice in the future. In the current study, we report our 15 years of experience in treating SFAAs, with a focus on the outcomes of patients undergoing open repair versus endovascular repair.

Methods

This was a retrospective, observational, single-centre study. We analysed our institutional electronic database (Ormaweb O4C, Dedalus, Firenze, Italy) to identify all patients who underwent surgical repair for true SFAA with either open or endovascular approach between January 2005 and March 2021. The search was performed using the 442.3 ICD-9 code, which refers to lower limb aneurysms, and then we selected only the SFAAs for the study. Paper-based and electronic medical records were reviewed with regard to their demographics and comorbidities.

The primary endpoints were technical success, which is defined as the absence of any perioperative complications related to limb and cardiovascular events; limb salvage, which is defined as the absence of major limb amputation during the follow-up; and primary patency, which is defined as the absence of restenosis >40% or peak systolic flow >150m/s on ultrasound at the graft and anastomosis in the open group and at the landing zones of the stent graft in the endovascular group. The secondary endpoints included major adverse cardiac events (MACE), survival and hospitalisation time. Follow-up consisted of clinical and ultrasound examinations at one, three and six months and annually thereafter.

Results

We identified 49 SFAAs in 40 patients treated between January 2005 and March 2021. Approximately 90% of the SFAAs were identified in men (36/40). The mean age at the time of diagnosis was 73.3±10.1 years. The demographic data and comorbidities are presented in Table 1.

On admission, 31 (77.5%) patients presented with a history of aneurysm or current aneurysm in another anatomical region (see Table 2). Most SFAAs were located in the middle and distal thirds. The mean diameter was 5.41±3.64cm (2.7–15.5cm). Overall, 30 (61.2%) patients with SFAAs were symptomatic; 3 presented with ruptures, and 6 had signs of limb ischaemia due to thrombosis (4 cases) and distal embolisation (2 cases). Most of the SFAAs (21 cases) presented with symptoms due to “mass effect”, such as leg swelling and pain pulsatile mass. Finally, 19 patients with SFAAs were asymptomatic and referred to our institution after instrumental examinations were performed for other medical conditions. Ultrasonography was the first instrumental examination in all symptomatic SFAA cases and in ten asymptomatic cases. Computed tomography (CT) of the aorta, iliac arteries and arteries of the lower limb was performed to better evaluate the SFAA and identify other aneurysms. The remaining nine asymptomatic SFAAs were discovered by CT scan in eight cases, and magnetic resonance imaging was performed for other medical conditions.

Discussion

SFAAs are rarely reported because these aneurysms often remain asymptomatic and continue to grow until they reach a considerable size. They present mainly with symptoms of mass compression of the adjacent vein and nerve structures and rarely with rupture.⁴ The remaining cases presented with signs of lower limb ischaemia due to thrombosis of the aneurysm sac or distal embolisation, thus increasing the risk of limb loss; this situation was independent of the aneurysm diameter.^1–3 Most studies consist of case reports, and few papers have reported a case series. We report one of the largest case series from a single centre and compared the outcomes of open and endovascular approaches for true SFAAs. In our series, the clinical limb presentation and location of the SFAA did not differ significantly from those reported in the current literature.⁵ As reported in the guidelines, there is a high consensus for the repair of symptomatic SFAAs to remove the embolic source, eliminate any mass effect and restore limb perfusion.⁶ By contrast, there is still no consensus on the treatment for asymptomatic cases.¹ Several surgical approaches have been described in the literature; however, the open approach remains the mainstay of treatment and has been used in almost 70% of all cases reported in the literature and in 73.4% of cases in our experience. These approaches include several techniques, such as aneurysm ligation without revascularisation, especially in patients with high surgical risk (literature vs our centre was 7.3% and 6.1%, respectively); primary amputation (rarely applied in 3% of cases); and aneurysmectomy with revascularisation using a prosthetic or vein graft. In both our series and the literature, prosthetic material, particularly ePTFE, represents the graft material that was most utilised for reconstructions, and an interposition configuration rather than a bypass was preferred.

Endovascular treatment has gained popularity in the last five years, accounting for 52.6% of SFAAs reported in the literature^5,7 and representing 26.5% of cases in our series. Our study demonstrated a significant difference in in-hospital stay compared with the open-to-endovascular approach. This is an expected outcome considering that most of the procedures are performed under local anaesthesia and percutaneously or by the femoral artery cutdown technique, which has been demonstrated to be a safe and less invasive approach that results in less postoperative pain and faster mobilisation.⁸ For these reasons, this minimally invasive approach is advantageous, especially in the elderly and frail patients as in our case series. However, in the present study, we did not notice any statistical differences in mid- and long-term survival or MACE rates between the two groups.

Perini et al² reported one of the largest case series with a five-year follow-up period and an estimated five-year graft patency rate of 85% after open repair. In our series, the primary patency rate in the open group was 93.7% after one year and 81.2% after five years. In the endovascular group, the primary patency rate was lower at 12 months but was not statistically significant (p=0.2). The number of cases treated with the endovascular approach is too small to draw solid conclusions. However, as in our experience, there was a strong selection of cases undergoing this kind of treatment, thus resulting in SFAAs mainly located in the middle third of the SFA. In the open group, there were more complex aneurysms in the distal third of the SFA and both the middle and distal thirds of the SFAA. The involvement of the popliteal artery was the most important factor in 12 cases. Moreover, the two stent graft thromboses in the endovascular group occurred in two patients who presented with PAA. In the remaining cases, primary patency was 100% during the entire follow-up period. The risk of stent graft occlusion after endovascular treatment of PAAs is high, is well described in the literature, and is related mainly to forces exerted on the stent during knee flexion, which leads to continuous stress on the stent graft structure.^9–11 Considering this aspect, open revascularisation in our experience demonstrated excellent results in complex SFAAs in the long term regarding primary patency and limb salvage rates.

The main limitation of this study was its small sample size, which was related to the rare frequency of these aneurysms. The second limitation is related to the retrospective nature of the study, which led to a bias in offering an endovascular approach for aneurysms located mainly in the middle third of the SFA.

Conclusions

The endovascular approach is becoming increasingly popular and could be a valid alternative for isolated SFAAs. It offers similar primary patency and limb salvage as open surgery and short hospitalisation times. By contrast, open revascularisation remains a valid approach, particularly for complex SFAAs and ipsilateral PAA.

Author contributions

Dr Gladiol Zenunaj and Luca Traina share the first authorship. Conception and design: GZ, Analysis and interpretation: AC, GB. Data collection: AMC, GB. Writing the article: LT, GZ. Critical revision of the article: VG, RS. Final approval: VG. -Overall responsibility: VG, LT.

References